That said, it's a tough topic, because regressions tend to really annoy
people, they feel "WTF, this always worked, WhyTF is it no longer working
now?", even though from a purely practical point of view, unfixed bugs (and
not working on some hardware is practically speaking a bug, even though
technically it's a missing feature) are much worse because there's no
working build to revert to.

Yes that is what I've done too (revert back to F-9 Xorg), even though I've been
actively working with airlied (congrats with your kid once more) to get things
in shape for F-10 and I believe we are in ok shape wrt 2d in F-10 3d is simply
not usable in F-10, and since I maintain many games in Fedora I need working 3d.

Didn't I fix the 3D already so it didn't crash for those apps (in
7.2.0-15)? or is it just slow?

I've mainly been using rawhide, where the bug definitely still exists (and I do
not have modesetting working in rawhide at all). I've just downgraded, the
kernel, libdrm, xorg-* and mesa-* to F-10 packages. That does give me working
3D without modesetting (which is new to me), but 3d still fails with
modesetting (hard hang when running blobAndConquer). Could you do to rawhide
whatever you've done to F-10 mesa? Running rawhide kernel + rawhide libdrm +
F10 xorg-* + F-10 mesa seems to work well. Better then with Rawhide X + mesa.
Regards,
Hans